ABB RELION REX640 Technical Manual page 341

1MRS759142 C
REX640
Technical Manual
GUID-999F7D36-4C98-4A31-9062-1E364C8E8935 V1 EN
Figure 187: Single-phase earth fault, phase A
In an example case of a two-phase short-circuit failure where the fault is between
phases B and C, the angle difference is measured between the polarizing quantity U
and operating quantity I
GUID-53CAA4AE-0268-4DC5-A309-5C8CBD721AC3 V1 EN
Figure 188: Two-phase short circuit, short circuit is between phases B and C
- I in the self-polarizing method.
B C
Section 4
Protection functions
BC
335